How to submit a pull request?

Hi, I'd like to submit a pull request with a proposed change. I found that the nic.cz GitLab instance allows me to log in with my GitHub account (and further to create my own GitLab account there). When I do this, the GitLab software tells me that I can submit merge requests with a special per-user e-mail address, but this doesn't appear to work. Perhaps this is because my account isn't a member of the BIRD project, and only project members are permitted to do this? Is there a proper way for the public to propose changes via GitLab and that special e-mail address, or should patches be posted to this list, or submitted somewhere else? Thanks!